Teinaava will point out Bogwater on their map, where the Argonian, named Scar-Tail, is hiding. When finding the camp, the Hero can choose to kill Scar-Tail immediately, or talk to him. He will offer the Hero a sum of money (equivalent to the sum Teinaava will reward them).

If the Hero chooses to leave him alone and bring the heart of another Argonian, which can be taken from the body of a dead Argonian nearby, he will tell the Hero about his hidden money.

It is also possible to kill Scar-Tail, take his heart and his money (it is hidden in a hollowed-out rock nearby), and then return to Teinaava. He will reward the Hero with the Boots of Bloody Bounding.

I must journey to the southeastern tip of Cyrodiil, to a swamp known as Bogwater. There I will find a renegade Shadowscale known as Scar-Tail. I must kill Scar-Tail, and return his heart to Teinaava.

Update: If the Hero agrees to help Scar-Tail:

I have agreed to spare Scar-Tail's life. I must take the heart of the dead Argonian assassin, and present that to Teinaava instead. To thank me, Scar-Tail has shared the secret hiding place of his treasure -- in the hollowed-out rock near Bogwater campfire.

Update: Upon obtaining an Argonian heart:

I have obtained the Argonian's heart. I must now return to the Dark Brotherhood Sanctuary in Cheydinhal and present it to Teinaava.

Update: If Scar-Tail is killed:

Scar-Tail has been killed. I must now return to the Dark Brotherhood Sanctuary in Cheydinhal and present his heart to Teinaava.